ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%28%26%2361%3BO%29%28N%29NC%28%26%2361%3BO%29O/file?format=sdf&get3d=True -- C%28%26%2361%3BO%29%28N%29NC%28%26%2361%3BO%29O could not be loaded.